US2335640A - Operating mechanism for discharge lamps - Google Patents

Description

Nov. 30, 1943. F. D. BRYANT OPERATING MECHANISM FOR DISCHARGE LAMPS Filed July 21, 1942 2 Sheets-Sheet l yams,

Inventor: FT" ank D. Br 5 JV 6. J

y ;is Attorney Nov. 30, 1943. F, D.- BRYANT OPERATING MECHANISM FOR DISCHARGE LAMPS Filed July 21, 1942 2 Sheets-Sheet 2 Inventof Frank I). Br

b f/ 6i y mttorney Patented Nov. 30, 1943 UNPTED STATES PATENT OFFICE.

2,335,640 OPERATING MECHAHQM FOB DISCHARGE LAMPS Frank D. Bryant, Syracuse, N. Y.,

General Electric New York nssignor to Company, a corporation of Application July 21, 1042, sens: No. 451,698 3 Claims. (cL zoo-s) My invention relates to an operatingmecha of the switch mechanism looking along the line |l of Fig. 3; Fig. 2 is another view of the switch mechanism looking along the line 22 of Fig. 3; Fig. 3 is an end view of the switch; Fig. 4 is an exploded view showing the switch elements, Figs. 5 and 6 illustrate a portion of the switch mechanism in various operating positions, and Fig. 7 is a diagrammatic view showing one way of con-' necting my switch into an operating circuit for a fluorescent lamp.

Referring to the drawings, the switch mechanisnrdesignated generally as' I0 is housed within a casing l I of any suitable" insulating material, such as a molded plastic. As shown in..Fig. 3, the casing is made in twoparts held' together around the mechanism bybolts i2, Within-the casing is a supporting .yoke l3 mounted on the end of a hollow. stud ll which receives and guides a pull chain ii for manually operating the switch mechanism.

The two arms ot the yoke 13 are each provided with integrally formed spaced projections I! which act as supports for, spaced insulating disks or rings I8 and I 9. The disks are formed with openings while the projections are likewise formed with openings 2| both oi which receive fastening bolts held in position by nuts 23. The disks l8 and I! are formed of suitable low cost insulating material, such as sheet fiber, from I which they may be punched. Each disk is formed as an annulus provided with a diametrical web 24 formed with an opening 25 for receiving a pivot'or arbor 26. In mounted position, the disks l8 and I! are spaced apart on opposite sides of the yoke, as shown in Fig. 3, and the arbor 26 extends between the members to form a pivot for the'movable part or the switch mechanism to be described presently.

The web 24 of the disk l8 carries a contact member 21 in the form of a curved spring blade which extends outwardly from the web to a position adjacent the rim of the annulus. Electrical connection to the contact member is made possible through a screw 28 to which a conductor 28 is connected, as shown by Fig. 1. On the oth- .ried by a plate turn, is rotatably mounted on the pivot 26. shorting member is whichenxases er side of the disk I 8 at a point opposite the contact 21 is another contact member 30 which is fastened to the rim of the disk by a rivet I I. The contact member Ill likewise has a curved portion located adjacent the with the contact member 21 forms an electrical circuit when a conducting member is passed between them. A Jumper 32 is electrically connected to the contact 30 through the rivet 3 I; this Jumper carries a terminal screw 33 for making an electrical connection with a conductor 3|. Electrical connection between the contacts 21 and 30 is eilected by means of a shorting member II car- 36 of insulating material which, in

The base portion or the fastened to the plate 38 in any suitable manner, as by rivets 31 while that portion of the member the contacts is offset from the plate and is--reversely bent to U-shape so that it easily passes between the contact members 21 and II and makes contact with each blade to complete an electrical circuit .therethrough. A washer 3! of insulating material separates the plate II from the disk I! and prevents binding so that the plate rotates easily.

The web 24 of the disk llalso carries a contact member 40 diametrically opposite the contact 21. The contact lll is formed as a curved spring blade, the same as the contact 21, and extends outwardly from the web to a position adiacent the rim of the annulus; it carries .a terminal screw 4| to which an electrical connection is made as by a conductor 42. ,An additional spring blade contact 43 is carried by the disk I! on the side opposite the contact M. The contacts 40 and II are adapted to be bridged by a shorting member 44 carried by the rotatable plate ll. In allrespects, the shorting member ll corresponds to the previously mentioned shorting member 35 and is similarly mounted on the plate. However, it is insulated from the shorting member II by a portion of the supporting plate 38. Contact member 43 is fastened to the rim of the disk by a rivet 43 which likewise holds in position a conducting Jumper 45 carrying a terminal screw 48.. A con-. ductor 41 provides an electrical connection with the terminal screw.

The other disk I! is likewise provided with contact members comprising spaced spring blades it and 49. Each blade is secured to the web 2| in any suitable manner, as by a rivet i0 and is curved outwardly to a point adjacent the rim of opposite each other on the rim of the disk and together same side of the disk. As shownby Fig. 2, the

. contact 48 carries a terminal screw for receiving a conductor 52 while the contact 49 likewise carries a terminal screw 53 to which a conductor 54 is connected.

Mounted for rotation on pivot 26 is a carrier or disk 55 of insulating material which carries a contact or shorting member 56 adapted to engage the fixed contact blades 48 and 49 for establishing a circuit therebetween. To this end, the shorting member is provided with opposed arms 51 which ride over the surfaces of the fixed contact members as the carrier is rotated. The shorting member is secured to the carrier in any suitable manner, as by rivets 58 and the center portion is hollowed out, as indicated at 59 so that it is electrically insulated from the pivot 26. A washer 68 of insulating material is disposed between the disk l9 and the rotatable carrier 55 so that the latter rotates freely.

The disks l8 and 19 are mounted on the yoke 13 in the manner already described and the carrier 55 and plate 36 are mounted for rotation between them with the contacts on the rotatable members cooperating with the corresponding fixed contacts carried by the disks. Both the plate 36 and carrier 55 are provided with an annular flange 6| which, when these elements are assembled together, provides a trough or raceway for the pull chain I5 of the operating mechanism now to be described.

As shown in Figs. 3 and 5, the pull chain extends around the perimeters of the plate 36 and carrier 55 and is connected to one end of a coiled spring 62 by a link 63. At itsotherend,

' the spring is secured to a clip 64 struck up from the yoke IS. A pin 65 is carried by the link and, in assembled position, is seated in a groove or opening 66 formed in the edge of the plate 36.

61. The operation just described means that upon continued pulls on the chain, the plate 36 and its associated contacts are moved to circuit closing position and then released to initial open position but that the carrier 55 and shorting contact 56 are moved in step-by-step movement to open and closed position, alternately.

As shown by Figs. 3 and 4, the assembled switch mechanism is held in position in the housing H by bolts 69 extending through opening 10 in the disks l8 and i9 and threaded to bosses 11 up- The pin is also adapted to cooperate with one.-

way cam surfaces 61 formed at spaced points around the perimeter of the disk or carrier 55 and constituting a means to form a ratchet connection with the pin 65. In the instant case,

four of such cam surfaces are provided correspending to four positions of the shorting member 51 two of which correspond to the "011 and on positions of the switch, respectively.

Initially; one of the cam surfaces 61 will be in alignment with the groove 61, as shown in Fig.

5, and the pin 65 will be seated therein. The contacts 35 and 44 will be in alignment with the arms 51 of the shorting contact 56. This means that a pull on chain 15 against the action of spring 62 will rotate the plate and carrier 55 through an angle of 90 so that the contacts 35 and 44 are moved to position between the fixed contacts on disk I8 and simultaneously the arms 61 engage the fixed contacts. 48 and 49 on disk wise direction, in the showings of Figs. 4 and 5 is limited by engagement of the offset contact 35 with the edge of the web 24 of the disk 18. Upon release of the pull chain. the spring 62 will rection. Since the pin 65 remains in groove 68, the plate 36 will be returned to its original position but as for the carrier 55, the pin will slide ofl the one-way cam surfaces onto the perimeter I9.. Rotation of the elements in a counterclockg0 move certain of the elements in the opposite di- 5 ofthe carrier, as shown by Fig. 6, and will be 7 returned for engagement with the next succeedingcam surface 61. During this operation, re-

turn movement of the carrier 55 is prevented by a spring blade 68 mounted on the yoke and which engages an app p iate one of the cam surfaces 76 standing from a wall of the housing. One manner in which the switch may be connected into an operating circuit for fluorescent lamps will now be described.

Referring to Fig. 1, I have shown two fluorescent lamps 13 and 14 operatively connected in circuit with my switch and with a ballast B of a type now available commercially. The ballast is provided with a reactor 15 having a lagging power factor connected to lamp 18 while a second reactor 16 having a leading power factor, due to the capacitor 11, is connected to the other lamp 14. A compensator 18in the form of a reactor adds inductance to the heating circuit of the second lamp to insure quick starting. The ballast just described forms no part of my invention since, as aforementioned, it is of a type now commercially available. Flourescent lamp 13 is provided with heating filaments 19 and at opposite ends thereof while the lamp 16 is:

likewise provided with spaced filaments 8i and 82. The manner in which the switch operates to start the lamps will now be described, it being noted that in the diagrammatic showing of Fig. '1 the switch is in start position with the contacts on the rotatable members 56 and 55 in engagement with the corresponding fixed contacts carried by the disks l8 and 19.

When the chain 15 has been pulled downwardly to move the contacts on the rotatable member to circuit closing position, current flows from one side 83 of an alternating current supply line to the reactors 15 and 16 of the ballast. Current from reactor 15 flows through conductor 84 to filament 86 at one end of the lamp 13, then by conductor 34 to fixed contact 85, through contact 35 on the rotatable carrier 35 to fixed contact 21, then by conductor 28 to the filament 19 at the other end of the lamp, then by conductor 52, fixed contact 68, movable shorting member 56, fixed contact 49 and conductor 54 to the other side 85 of the supply line. Simultaneously, current fiows from reactor 16 by a conductor 86 to filament 82 at one end of the lamp 14, then by conductor 42 to fixed contact 46' through movable contact 64, fixed contact 43, conductor 41 to the compensator 18, then by a conductor 81 to filament 8| at the other end of the lamp, by conductor 88 to conductor 52 and then through fixed contact 48, shorting member 56, fixed contact 49 and conductor 54 to the other side 85 of the supply line.

It should be manifest that the arrangement is such that as long as the chain 15 is held in pulled-down position, current will flow through the electrodes of both fluorescent lamps in the manner just described to preheat them. Usually, this preheating time is on the order of one to five seconds and the chain should be held pulled down for this period of time. Upon release of the operating chain l5, the carrier 55 and short ing member 56 will remain incircuit closing position but the plate 55 and contacts 35 and 65 will be returned to their initial open position :quick pull on the chain l so that I used with two fluorescent so that the circuits through the fixed contacts "-30 and 40-, respectively, will be opened. This opens the circuits across the filaments of the lamps so that the reactors and 18 provide an inductive kick causing a glow discharge to v strike between the filaments of each lamp, lighting the lamp. When this occurs, the circuit through the operating mechanism is as follows.

Current fiows from reactor 15 through conductor 84 to the filament 80 across the glow discharge in lamp 1; to filament 15, then by conductor 52, contact 48, shorting member 58, contact l9 and conductor 54 to the other side of the supply line. Simultaneously, current flows Jroin reactor 16 through conductor 86 to filament 82, then across the glow discharge in lamp M to filament 8|, conductor 80, conductor 52, contact 4|, shorting member 56, contact l9 and 'conductor II to the other side of the supply line.

When it is desired to turn on the lamps, the operating chain I5 is again pulled downwardly so that the pin 65 engaging in the next succeeding cam surface 61 moves the shorting member I to circuit opening position between the contacts 48 and 49. Even though the rotatable conoil by a simple operation of the pull chain I 5' which operates the switch mechanism in sequence to on and "cit" positions. When the switch is pulled on, it is only necessary to hold the pull chain down for a few seconds to effect preheating of the lamp filaments. Should the lamps not light on the first operation of the switch mechanism, the mechanism may be quickly moved through the "oil!" position by a the next pull in position to my switch as being lamps, it should be manifest that the switch will operate equally as well with only a single fluorescent lamp simply by omitting the connections to one oi" the pairs or contacts 21-" or -43. The mechanism will 88- place the mechanism start the lamps.

While I have illustrated is or a type which is welladapted for use in ordinary pull chain sockets such as are used to a considerable extent in fioor lamps.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A switch mechanism comprising an insulating casing, two axially spaced insulating plates with contacts thereon secured in the casing, a first and a second disk with shorting members thereon for cooperation with said contacts being rotatably supported between the insulating plates and forming a raceway between them, and means for rotating the disks to effect electrical connection between the contacts and the respective shorting members comprising a pullchain engaging the raceway, a spring connecting the chain to the casing, a pin fastened to the chain andmeans on the first disk forming a positive drive between the .pin and the first disk and means on the second disk forming a ratchet connection between the pin and the second disk to rotate both disks upon pulling of the chain and to cause return of the first disk to its initial position upon subsequent release of the chain. 2. A switch for operating a discharge lamp having spaced filaments comprising an insulating casing, first and second pairs of contacts secured to the casing, first and second disks each with a shorting member thereon for cooperation with the respective pairs of contacts, the first disk having an opening, the second disk having circumferentially spaced cam surfaces, spring means for biasing the first disk into a fixed angular position, and means for rotating both disks against said biasing spring to establish connection between the pairs of contacts and the respective shorting members and subsequently to cause the first disk to return to its original position by action of the spring, said means including a pin projecting through said opening and engaging said cam surfaces.

3. A switch mechanism comprising a casing, first and second pairs of contacts secured to the casing, first and second disks with shorting members thereon for cooperation with the respective pairs of contacts,

a pullchain connected to the casing, a pin secured j to the chain,

positive connecting'means between the pin and the first disk and ratchet connecting means between'the pin and the second disk.

FRANK D. BRYANT.

means rotatably supporting, the disks within the casing, said disks having

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